高速动车组角焊缝应力集中的识别方法

Identification Method for Stress Concentration on Fillet Weld of High-Speed EMU

针对高速动车组焊接构架角焊缝处应力集中无法采用名义应力法识别的问题,基于结构应力法,将角焊缝焊趾处的非线性应力分解为满足外载荷平衡的结构应力和自平衡的缺口应力,然后根据力的平衡方程得到各节点力及其力矩与线力及其线力矩间的对应关系,进而推导出结构应力的计算公式,并给出角焊缝应力集中识别流程;基于所给出的算法和识别流程,采用C/C++以及ANSYS软件提供的APDL语言开发出焊接结构应力识别专用软件WSS,对某高速动车组焊接构架上诸多角焊缝应力集中进行识别,验证了基于结构应力的角焊缝应力集中识别方法不仅能给出应力集中的具体位置,还能给出具体的应力峰值及其对应的疲劳寿命,可用于优化高速动车组焊接构架的抗疲劳设计。

Since the stress concentration on the fillet weld of the welded frame for high-speed EMU cannot be identified by nominal stress method,based on structural stress method,the nonlinear stress at weld toe is first decomposed into two parts,including structural stress in external load equilibrium and notch stress in self-equilibrating.Then,according to the equilibrium equation of the force,the corresponding relationships between nodal forces and moments,and line forces and moments are calculated.The calculation formula of structural stress is further derived and the identification process of stress concentration on fillet weld is given.On the basis of the proposed formula and identification process,a special software WSS for stress identification in welded structure is developed with APDL language provided by C/C＋＋and ANSYS software.The stress concentration on the fillet weld of the welded frame for a high speed EMU is identified.It is verified that the identification method based on structural stress not only can identify the specific position of stress concentration,but also can calculate the specific stress peak and corresponding fatigue life.It can be used to optimize the anti-fatigue design of the welded frame for high speed EMU.